Do more side effects signal better breast cancer outcomes?

The occurrence of medication side effects, such as vasomotor symptoms and arthritis, in women who received endocrine treatment for breast cancer may indicate a decreased risk of cancer recurrence and act as a marker for treatment success, according to a study published online Oct. 30 in The Lancet Oncology.

Jack Cuzick, PhD, of the University of London and colleagues examined the association between self-reported vasomotor or joint symptoms and breast cancer recurrence among 3,964 participants in the Arimidex, Tamoxifen, Alone or in Combination (ATAC) trial.

Among the 37.5% of women reporting new vasomotor symptoms at the 3-month follow-up visit, recurrence of breast cancer was significantly lower than for those not reporting symptoms (223 during 10,752 women-years of follow-up vs. 366 during 11,573 women-years of follow-up). Similarly, among women reporting new joint symptoms, breast cancer recurrence was less frequent than for those not reporting symptoms (158 during 9,242 women-years of follow-up vs. 366 during 11,573 women-years of follow-up).

Cuzick J, Sestak I, Cella D, et al. Treatment-emergent endocrine symptoms and the risk of breast cancer recurrence: a retrospective analysis of the ATAC trial. Lancet Oncol. doi:10.1016/S1470-2045(08)70259-6.